A new study led by Prof. WANG Faming from the South China Botanical Garden of the Chinese Academy of Sciences has shed light on the crucial role of soil microbes in carbon sequestration during mangrove restoration, offering a new microbial-driven perspective for enhancing "blue carbon" sinks.

The findings were recently published in Journal of Plant Ecology.

While mangrove restoration is known for its potential to lock away atmospheric CO₂, the processes governing the fate of this carbon in soils remain complex.

To address this knowledge gap, the team focused on a restored mangrove wetland on Qi'ao Island and found that restoration significantly reshapes the microbial community and its functions.

Their data revealed a 37.84%–56.67% increase in microbial carbon use efficiency (CUE) — a measure of how effectively microbes convert consumed carbon into their own biomass rather than respiring it back as CO₂. This shift is attributed to improved organic carbon quality and a fundamental change in microbial community structure, with communities transitioning from fast-growing "r-strategists" to slow-growing "K-strategists."

Notably, this enhanced microbial efficiency directly drives carbon storage. The study found that CUE was positively correlated with microbial necromass (dead microbial residue) carbon, explaining 73% and 69% of the variation in fungal and bacterial necromass carbon, respectively. While bacterial necromass increased more, fungal residues constituted the dominant portion of the newly formed microbial-derived carbon pool, underscoring the pivotal role of fungi in stabilizing long-term soil organic carbon.

The results demonstrate that mangrove restoration boosts soil carbon storage not only by increasing plant-derived inputs but also by optimizing microbial processing to favor carbon preservation.